1. Field of the Invention
The present invention relates a pedal device of a vehicle, particularly a pedal device that reduces difference in the pedal response due to the driver's driving propensity and fatigue of the ankle due to a repeated operation of the pedal, by adjusting the elastic force of a return spring providing a return force to the pedal arm.
2. Description of the Related Art
In general, a vehicle traveling is accelerated when the driver presses the pedal device and the pedal device is frequently pressed by the driver while the vehicle is traveling; therefore, research to improve the pedal response is being conducted.
Further, the pedal device for acceleration is mainly divided into a mechanical type and an electronic type. The mechanical acceleration pedal device includes an acceleration pedal that is pivotably mounted inside the vehicle room, a throttle mechanism that is provided in the intake system in the engine room, and a cable that is provided to transmit an operational force between the acceleration pedal and the throttle mechanism, connecting them.
On the other hand, an electronic acceleration pedal device includes an acceleration pedal that is pivotably mounted in the vehicle room, a pivot angle detecting sensor, such as a potentiometer, which is attached to the acceleration pedal to detect in real time the amount of pivots of the acceleration pedal.
However, in the acceleration pedal devices as described above in the related art, according to the mechanical acceleration pedal device, a hysteresis, when a reaction force applied to the driver pressing the pedal is smaller than a reaction force applied to the driver releasing the pedal due to the friction between a wire and a tube in the cable at the same time the pedal is being pressed and released, is caused. However, this has minimal effect on tuning the pedal effort.
On the contrary, according to the electronic acceleration pedal device in the related art, the amount of reacting force applied when the driver presses or releases a pedal depends on only the natural elasticity of the return spring that elastically returns the pedal arm, and the amount of reacting force is set on the basis of the pressing force for acceleration rather than on the basis of the releasing. Therefore, the electronic acceleration pedal device that generates the same magnitude of reacting force while pressing and releasing the pedal in the related art, increases the fatigue of the driver's ankle as the driver repeatedly presses and releases the pedal. As a result, this deteriorates the response of the pedal.
Further, since the reacting force depends on the natural elasticity of the return spring in the electronic acceleration pedal device in the related art, it is difficult to freely perform the tuning of pedal effort according to the driver's preference.